When my DS was 2 years old there was no stopping him confidence wise. But for the past year or so he has really started to withdraw from group situations and has even stopped being playful with me and his Mum. The change in behaviour may have coincided with the arrival of his little sister when he was two, but his behaviour didn't really change until she was around 3 months old so I don't think they're directly related events.
Typical behaviour is when we go to nursery (3 days a week) and he walks into the kitchen for breakfast. He can be laughing and giggling right until the point we get to the door, then he shrinks back, hides behind our legs or puts his hands over his eyes and starts crying. He'll sit at the table and sulk and sometimes won't even eat any breakfast. Then the nursery staff tell me that within 10 minutes he's fine and usually fine for the rest of the day.
Otherwise we'll be visiting friends for a playdate, friends he's known since he was a few months old, we all live local to each other. He refuses to join in with his friends and can often cower or sulk in the hallway. Nothing we do can bring him out of it, no matter how much encouragement we give him or tell him there's nothing to worry about, he can sulk or withdraw for an hour or so.
He can also get very angry. We'll be playing nicely one minute, my son having initiated something like making monster noises. Then when I say "Aaaah! There's a xxx-saurus after me!" he'll get out the pet lip, sulk and shout "I just don't want you to talk to me!". Other times we'll get 50-minute toddler-style tantrums with kicking, biting and scratching over simple things like getting ready in the morning.
He's due to start school in September, he'll be the youngest in the year and I'm very worried about how he'll cope if he still has these confidence issues when starting school. What as parents have we gotten so wrong to turn a lovely, happy confident little boy into such a troubled child?